1. Field of the Invention
The present invention generally relates to a work-sheet holder connecting apparatus for a sewing machine and particularly to such an apparatus which connects a work-sheet holder to a feed member which is fed by a feeding device of the sewing machine.
2. Related Art Statement
Japanese Patent Application laid open for inspection under Publication No. 6-126054 discloses a multiple-head embroidering machine as an industrial sewing machine suitable for sewing a predetermined pattern or embroidery.
The above sewing machine includes a plurality of sewing heads which are provided at a regular interval in an X direction, a plurality of sewing beds corresponding to the sewing heads, respectively, a feeding device, and a common feed member which is fed by the feeding device in the X direction and a Y direction independent of each other and to which a plurality of work-sheet holders are connected. Each sewing head includes a needle-bar case which accommodates a plurality of needle bars for supporting a plurality of sewing needles which convey color-different embroidering threads, respectively. The needle-bar case is displaceable in the X direction. The sewing machine additionally includes a main shaft and a main motor for driving or rotating the main shaft so that the rotation of the main shaft is transmitted to an upper and a lower shaft of each pair of sewing head and sewing bed.
In the prior sewing machine, the work-sheet holders are connected to the common feed member via a plurality of connector members, respectively. The connector members are connected to predetermined positions on the feed member, respectively. Each of the work-sheet holders is detachably attached to a predetermined position on a corresponding one of the connector members. A work sheet on which an embroidery pattern is to be formed is set on each of the work-sheet holders. Thus, the work-sheet holders are moved by the feeding device in the X and Y directions in synchronism with each other via the feed member and the connector members.
Therefore, an operator must set a plurality of work sheets on the work-sheet holders, respectively, in the same way, i.e., in such a way that respective embroidering areas of the work sheets have identical positions relative to the corresponding holders in the X and Y directions and have identical angular positions relative to the corresponding holders about corresponding vertical axis lines perpendicular to the X and Y directions. If a work sheet is set on a work-sheet holder in a different way, the work sheet must be repeatedly reset on the holder until the work sheet is set in the same way. This operation is very cumbersome and time-consuming, thereby lowering the work efficiency of the operator.
Meanwhile, U.S. Pat. No. 5,415,116 discloses another multiple-head embroidering machine for forming an embroidery pattern on a headgear such as a baseball cap. The second sewing machine includes a plurality of frame devices to which a plurality of headgear holders are detachably attached, respectively, and which are connected to a first feed member which extends in an X direction and is fed in a Y direction by a Y-direction feeding device and a second feed member which also extends in the X direction and is fed in the X direction by an X-direction feeding device. Each headgear holder holds a headgear on which embroidering stitches are to be formed. Thus, the headgear holders are moved in the Y direction and are rotated about respective axis lines parallel to the Y direction via the first and second feed members, respectively. In this case, too, the frame devices are connected to predetermined positions on the first feed member, and each of the headgear holders is connected to a predetermined position on a corresponding one of the frame devices. Thus, the second sewing machine suffers from the same problems as the above-identified problems of the first sewing machine.
Even in a single-head sewing machine, a work sheet must be set on a single work-sheet holder such that an embroidering area of the work sheet is positioned with accuracy relative to the holder. Otherwise, an embroidery pattern is formed at an inaccurate position on the work sheet.